Embodiments relate to a semiconductor device including a metal dummy pattern and a thin film resistor (TFR), and a method of fabricating the semiconductor device.
Passive devices perform important functions in an electronic system. Recently, the making of miniaturized, multi-functional, and economical electronic appliances is giving rise to requirements for passive devices to be fabricated in the form of an array, a network, and a built-in passive device that is recently popular. Such passive devices sense, monitor, transmit, reduce, and control voltage.
Resistors as passive devices suppress a flow of electric charge current, thereby controlling the amount of current. Such resistors may be classified into a thin film resistor including a pattern formed with a deposited thin metal layer, and an active layer resistor including an active layer region. Such a thin film resistor is disposed between metal lines of a semiconductor device.
When a semiconductor device is fabricated, a metal dummy may be added to reduce a density difference of a metal on a semiconductor substrate and prevent a high difference during a chemical mechanical polishing (CMP) process, thereby forming a uniform array.
FIG. 1 is a plan view and a cross-sectional view illustrating a semiconductor device including a metal dummy and a thin film resistor in the related art. Referring to FIG. 1, the semiconductor device includes a semiconductor substrate 10, a first dielectric 20 disposed on the semiconductor substrate 10, a lower metal line 30 disposed on the first dielectric 20, and a metal dummy pattern 40 randomly formed. A second dielectric 50, a thin film resistor 60, a third dielectric 70, an upper metal line 80, and a via 90 may be sequentially formed on the lower metal line 30 and the metal dummy pattern 40.
While the semiconductor device is fabricated, the thin film resistor 60 may have an irregular pattern profile according to whether a metal dummy is disposed under the thin film resistor 60. That is, when a metal dummy is randomly formed, and then an exposure process is performed to form the thin film resistor 60 on the metal dummy, a portion of light may pass through the thin film resistor 60 having a small thickness. The light passing through the thin film resistor 60 is reflected by the metal dummy disposed under the thin film resistor 60, thus deforming a line of the thin film resistor 60.
FIG. 2 is an image illustrating a slope of a thin film resistor formed as described above. Referring to FIG. 2, while a portion of the thin film resistor in a region corresponding to a metal dummy pattern is uniform in slope, a portion of the thin film resistor out of the region corresponding to the metal dummy pattern is decreased in slope.
That is, referring to FIGS. 1 and 2, in a method of fabricating a semiconductor device including a metal dummy pattern and a thin film resistor in the related art, the thin film resistor may have an irregular pattern profile to jeopardize uniformity thereof, and thus, a resistance value required by a designer may not be satisfied.